Base
In a blender, process the macadamia nuts until they become a fine flour.
Add remaining ingredients, then spoon into tray and press down.
Pop into the freezer for 15 minutes and clean blender.

Filling
Drain cashews, then blend all ingredients together until smooth.
Pour on top of the base and freeze for a further 15 minutes.

Topping
Whisk cacao powder and oil together until smooth- you may need to add more coconut oil depending on how thin or thick the ganache is.
You can add 1 tsp coconut sugar if you desire, as it is quite bitter.
Top the slice with the ganache and store in the refrigerator until ready to slice and serve.